Lapping machine



NGV. 17, 1931.v H. s. INDGE ETAL 1,831,958

LAPPING MACHNE Fig. 1 y Qwwmm HERBERT S.INDGE SYDNEY PLAYER Nov. 17, 1931. H. s. INDGE ETAL LAPPING MACHINE Filed Oct. 19. 1928 2 Sheets-Sheet 2 'sul lIl il. il r 475,474

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gwomozs HERBERT S. INDGE wSYDNEY PLAYER Patented Nov. 17, 1931 UNITED STATES` PATENT oFr-lc HERBERT S. TNDGE AND SYDNEY PLAYER, O WSTBORO, MASSACHUSETTS, ASSIGNORS TO NORTON COMPANY, F WORCESTER, MASSACHUSETTS, A CORPORATION OF IAS- SACH'USETTS LAPPING MACHINE Application filed October 19, 1.928.

This invention relates to lapping ma.- chines ot the type in which a multiplicity of duplicate work pieces are mounted in a cage between two opposed laps. the cage andthe laps being relatively movable to cause a lap ping action.

ln order to place pieces ot work in the work retaining cage of this type of lapping machine, it is customary to move the upper lap away from the lower through a considerable distance. Owing to the weight of the upper lap, the operation of raising it either requires considerable effort on the part of the operator or involves considerable waste of valuable L time which should be utilized in producing the lapped articles.

It is therefore one object of this invention to provide a power operated lifting device capable of moving one of the laps toward or from thc other, and particularly one which ma y be manually controlled to regulate the distance through which one of the laps may .be moved in either direction, the lap being stopped automatically in any desired position relative to the work or to the other lap and held there until further adjustment is made A further object is to provide aJ lapping machine with both a power operated lifting mechanism for moving one of the laps and a manually operated mechanisnrwhich may be utilized for finely` adjusting the movable lap into a correct position relative to the work to be lapped.

The ordinary lapping operation is one in which the upper lap rests upon the work with particularly a manually controllable mecha-v nism capable of providing a pressure which Serial No. 313,549.

may be gradually varied from a very slight touch to a heavy thrust upon the work and whih may be quickly released whenever desire A further. object of the invention is to combine these various features into a lapping machine and thereby to produce a power operated, manually controlled machine which will be highly serviceable for lappin vari# ous types ot articles on a large sca e production basis.

A lapping machine made in accordance with this invention comprises two opposed laps having a work cage therebetween, which are relatively movable to lap the ieces of work held within the cage. One o the laps is movable toward or away from the other lap, and if the laps are horizontally arranged, the lower lap is preferably stationary and the upper lap is moved vertically toward and from the lower lap. The movable lap is moved by a power driven mechanism, and in order that the movable lap may be stopped in any desired position, a stopping device is provided which may be set as desired so that the movable lap may rapidly move to a predetermined position and be definitely held there until further adjust! ment.

The power operating mechanism preferably comprises a clutch controlling device which may be manually adjusted to any desired position so that when the movable laip has rapidly traveled to a given location the clutch will be automatically disen aged tostop any 'further power movement o the 1ap This driving mechanism also preferably in cludes a worm which is so arranged that, when the clutch has been disengaged, the weight of the lap will not cause any further descent, but the la will remain in that position until move either manually or by power. i

A further feature of this inventionA comprises a manually operable mechanism which may be employed either to move the lap throughout the entire distance desired or to finely adjust the position of the lap relative to the work after it has been brought nearly to a correct position by the power driven 100 termining the amount of actuating device, which may'be manually controlled toimpress any required pressure, varying from a mere touch to aheavy thrust,

upon the work during the lappingoperation.V

Referring Vto the drawings which illustrate one embodiment of the invention and in which like numerals indicate like parts:

Fig. 1 is a vertical elevation partly in section of the assembled lapping machine; f

Fig. 2 is an`enlarged view in section along the line 2.-2 of Fig. l showing the clutch and manual control' mechanism;

Fig. 3' is a fragmentary view of the hand wheel and scale associated therewith for depressure to be exerted upon the work;

Fig. 4 is a fragmentary section'taken along the line 4-4 of Fig. 1 for the upper lap and the associated parts therewith; 'f

Fig. 5 isA a fragmentary elevation showing y the relation ofthe clutch operating arm with the adjustabledevice which determines the position of the lap when the clutch is disen` ga ed; and

`ig. 6 is a fragmentary section taken along the line 6 6 of Fig. 3, showing the parts mounted upon the hand wheel shaft.

Referring more particularly to the embodiment illustrated, the lapping machine may be constructed in its general aspects similar to the machine illustrated in the United States patent to Indge No. 1,610,527, and this ma'- chine as shown in the prior patent and here illustrated comprises a base 10 upon which is mounted a lower lap 12 and an upper lap 14 and between which is arranged a work supporting cage 15. The lower lap may be stationary or rotatable insofar as the resent invention is concerned, and the wor cage i 15 will 'be movable or stationary in accordance with the nature of the movementimmounted for revolution relative to the laps'4 by means of the revolving posts 16 provided for thatpurpose, these being arranged as shown in the patent to-IndgeNo. 1,610,527. j

The upper lap 14 is'suitably mounted on asupport 18 and this support is adjustably carried on a' vertical shaft or spindle 2O which is mountedl for vertical movement relative to the lower lap. As illustrated, the spindle 20 has threaded on its lower end a cap 22 which supports two members 23 and 24 of'a ball and socket joint so arranged that the upper lap 14 may be adjusted to various positionsrelative to the plane of the lower lap and preferably for the operation of truing the upper lap when it is necessar that the two laps be brought into exact para lelism. These members may be left free for movement, if desired, so that the lap may continually adjust itself during a lapping operation to the plane of the tops of the work pieces. These members 23 and 24 contact on a substant-ially spherical surface 25, as illustrated in Fig. 1, and they are held in proper alignment by a series of screws 26 arranged to permit adjustment of the two parts relative to each other. The support 18 which carries the upper lap is fastened to the lower member of the universal joint 23 by means of further screws 28.

In order to permit vertical movement of the upper lap, the spindle 20, which is arranged to be revolved by means of a pulley 30 mounted on its upper end, is rotatably mounted within the housing 31 which projects laterally from the vertical casing 32 of the base as shown in Fig. 1. The spindle 20 is rotatably mounted in the sleeve 35 which is keyed to the housing by key 34 so that it may move only vertically. Suitable bearings 36 and 37 are arranged between the sleeve 35 and the spindle 20. These bearings are held in place v by a further sleeve 38 placed therebetween and surrounding the spindle 2O as will be evident upon inspection of Fig. 4 of the drawings. Collars 39 and 40 on the spindle serve to position the spindle and sleeve relative to each other. It will be noted that the supporting members 23 and 24 areclamped against the under side of the collar 40 (Fig. 1) and. that the upper member 24 is keyed to the spindle 2O so that it must rotate therewith.

One feature of this invention involves a power lifting device for moving the spindle vertically. In order that this may be accomplished, the sleeve 35 is provided upon one side with teeth 45 which mesh with a pinion 46 (Fig. 2) suitably fastened on the short shaft `47 journaled in the housing 31. A worm wheel 48 fastened on this shaft meshes with a worm 50 which is slidably keyed to a cross shaft 52 journaled inthe housing 31, as shown in Figs. 1, 2 and 6. This worm 50 is normally retained in position at the left-hand end of the shaft, as shown in Fig. l, by means of a spring 54 which is located between the end of the worm and the interior of the housing. These parts are therefore so arranged that when the worm is rotated in either direction,

the sleeve 35 and the upper lap carried there` by will be moved vertically toward or away from the lower lap. l

In order to move this upper lap by means of a power mechanism, a suitable power takeoff is provided to transmit power from the main driving shaft'of the machine to this worm. As illustrated, the main shaft 56 in the bottom of the machine may be connected the shaft 65 journaled in the upper portion' of the casing 32. This shaft 65 is connected through the gears 66 and 67 to-theshaft 52 which drives the worm 50.

A suitable clutch is provided to connect the shaft '65 with either of the pulleys`63 or 64. As illustrated, a friction driving clutch device may be utilized for this purpose comprising, as simply shown in the drawings, a double cone clutch member having conicalV faces which are arranged to engage corresponding conical recesses in one or the other of the pulleys 68 and 64. This clutch member 70 is slidably keyed to the shaft 65 and will therefore drive the shaft in one direction or the other depending upon which pulley it engages. The clutch may be controlled manually by means of a suitable yoke 72 which is thrown by the arm 73 mounted on the short shaft 74 which is journaled in the wall of the casing 32. On the outer end of this shaft 74 is fixed a crank arm 75 (Fig. 5) which is connected by a link 76 with a hand lever 77 pivotally mounted upon the housing 31 for convenient movement by the operator. Upon throwing the clutch into engagement with one or the other of the driving pulleys 63 and 64, the upper lap will be moved toward or away from the lower lap. Also it will be readily seen that,

whenever the clutch is thrown to a neutral position, this upper lap will remain in its new position because the rack 45 cannot drive the worm backwards, hence there is no danger whatever of the upper lap falling and injurin either operator or the work.

he invention further comprises a mechanism which may be set arbitrarily to stop the downward movement of the upper lap in anyv desired position relative to the lower lap-so that the operator need not give attention to this when it is not in working position. To this end, the handle 77 is fashioned as a bell crank lever which carries pivoted at the end'. of its short arm 80 a yoke member 81. This yoke member 81 projects through a suitable openingl screw t readed member 85 which is rotatably mounted on the sleeve 35,. The lower end of this screw 85 has collars 86 and 87 which position the screw relative to the projections- 88 and 89 on the sleeve andin which-the screw is rotatably mounted. A nut 90 is threaded upon the screw 85 above the-yoke member 81 and also is keyed in the keyway `91in the side, of the sleeve 35 so that .it cannot rotate. The 1 collar 87 projects to an accessible positionand* is provided with a series of holes inwhich a -zrpin may be inserted to rotate thescrew 85 any desired amount, thereby causing the nut.

90 to travel up or down the screw 85. l

in the housing 31 and straddles av tacts with it and throws the bell crank arm 77 to neutral position thus disengaging the clutch 70 and 'stop ing the upper lap in the desired position. g recedes from the lower, the collar 86 contacts with the yoke member 81, throwing the arm 77 to a neutral position, and thereby limits the upward stroke of the u per lap, thus saving the machine from possi le damage should the operator neglect to stop the upper lap in its travel. This mechanism makes it possible to raise and lower the' upper lap by means of a power driven mechanism. It is also feasible to raise and lower the upper lap by manually rotating the shaft 52, and the lap may bestopped in any desired osition by means of the hand lever 7 7 and he d there until the worm 50 is rotated to a further extent.

A further feature of the invention involves a mechanism whereby the o erator may cause shaft 52 is placed a hand wheel 100 which is loosely mounted upon the shaft and is adapted to engage it through suitable clutch teeth 101 (Fig. 3). By means of this hand wheel, the worm 50 may be rotated, when the clutch member 70 is in a neutral position, and the upper lap suitably adjusted. If the upper lap is lowered to rest upon the work and the power disengaged by manually or automatically throwing the hand lever 7 into a neutral position, and if the hand wheel is thereafter turned in such/a direction as to tend to force the upper lap downwardly, the result is to cause the worm 50 to slide longitudinally on the shaft 52 against the pressure of the spring 54 which pressure may be increased to any desired extent by propermanipulation of the hand wheel; Such rotatioirof the imilarly, as the upper lap icc with the work, tends to com ress' the spring 54 and serves therefore to maintain a pressure vupon the work during the lapping. operation. --In order to properlyfgauge' the pressureimf .partedbythe laps upon the'work, asuitable scale and pointer are'provided.' i This may comprise a scale 105 suitably'placed on' .theV ,edge of an opening in the outer housing of im f the machine asv shown in Fig. 8.-;. A'collar 106 i i on the worm 50 -is so located that` it willbe close to thescale 105 and therebyjshow the position of the' worm and -indicatethe pressure imparted to the springtohold' theA worm in suchl position.

By means of this construc'z'tionit possible to manually raise or lower the upper ap and after the lap has contacted with the work, it

may be forced against it with a heavy pressure orwith a very slight pressure. lf the operator wishes to alter the pressure during the lapping opera tion, he may rotate the hand vwheel 100 in the desired direction.

The operation of the machine will beueadily apparent. The operator may move lever 77 to engage the clutch 70, whereby the upper lap is rapidly lowered by power until it reaches a position just out ot contact with the work; whereupon the nut 90, having been previously adjusted in position, throws the lever 77 back to a neutral position by contacting with the yoke 8l fastened to the lever 77, thereby stopping the downward travel of the lap at the desired position. The operator may then lower the upper lap through the slight remaining distance by engaging the clutch 101 and revolving the hand wheel 100 in the required direction until the lap conta cts with the work. Further revolution of this hand wheel imparts the required pres- Sure upon the work by the laps, which may be determined by the pointer 106 upon the scale 105. lVhen the lapping operation has continued sufficiently, the operator throws the lever 77 into a reverse position thereby rapidly raising the upper lap bv power. lf he fails to 'disengage tbc clutch 70 by throwing lever 77 again to neutral position when the upper lap has been raised the `required amount, the collar 86 in its upward travel will engage the yoke 8l attached to lever 77 thereby throwing lever 77 to a neutral position and stopping the upper lap in its travel; y

The arrangement described is a simple mechanism which will serve to movethe upper lap either manually or by power and to a desired extent as predetermined by the position of a suitable stop, and the same mechanism will serve to apply a predetermined pressure upon the work. The laps 12 and 14 may be composed of any suitable material, such as iron employed with loose abrasive powder, or of bonded abrasivematerial similar to grinding wheels, it being understood that the nature and size of the abrasive grains and the type and hardness of the wheel bond may be such as are determined to be best for any particular operation.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A lapping machine comprising two opposed laps, a work cage therebetween arranged to hold a multiplicity of work pieces yin peripherally spaced lapping engagement therewith, said parts being relatively movable to lap the work, means for moving the laps relatively toward and from each other, adjustable mechanism for impressing a. predetermined pressure upon the work by said laps, and manually operated means for varying said pressure.

2. A lapping machine comprising two opposed laps having annular lapping surfaces, and a work cage therebetween arranged to hold a multiplicity of work pieces in peripherally spaced engagement with said surfaces, means to cause a relative lapping movement between the work and the laps, means for moving the laps relatively toward and from each other, positively acting pressure mechanism tending to force one lap toward the other and thereby impart a definite pressure upon the work by said laps, and a manually' adjustable device for varying the pressure minutely during the lapping operation.

3. A lapping machine comprising two opposed laps and a work cage therebetween which are relatively movable to lap the work, means to move one of the laps toward and from the other, a manually controlled pressure device arranged to exert a predetermined but variable pressure by the laps upon the work, and a device whereby said pressure is indicated at all times.

4. A lapping machine comprising two opposed laps and a rotatable work cage therebetween which are relatively movable to lap the work, means to move the work cage through an ever-changing path during its rotation whereby each work piece will be moved over the entire opposed lapping surfaces, a support for one of the laps permitting it to be moved towards and from the other lap, positively acting yieldable pressure mechanism tending to force one lap towards the other and thereby impart a definite predetermined pressure upon the Work by said laps and manually adjustable means for varying said pressure by minute increments to any desired extent.

5. A lapping machine cimprising two opposed laps and a rotatable work cage therebetween which .are relatively movable to lap the work, means to move the work cage through an ever-changing path during its rotation whereby each work piece will be moved over the entire opposed lapping surfaces during the lapping operation, a support for one of the laps permitting it to he moved towards and from the other lap, positively acting pressure mechanism including a spring tending to force the movable lap towards the other, and means to gradually vary the tension of said spring and thereby vary the pressure of the laps upon the work to any desired extent.

6. A lapping machine comprising two opposed laps and a work cage therebetween which are relatively movable to lap the work, a support for a lap permitting it to be moved toward and from the other lap, means for impressing a predetermined but variable pressure upon the work by the laps, and power operated mechanism for moving the laps relatively away from each other and thereby automatically releasing the pressure upon the work.

7. A lapping machine comprising two opposed laps and a work cage therebetween which are relatively movable to lap the work, power operated means for moving one of the laps relative to the other to vary the distance therebetween, and manually adjustable mechanism for exerting a variable predetermined pressure upon the work during the lapping operation.

8. A lapping machine comprising ltwo opposedlaps and a work cage therebetween which are relatively movable to lap the work, power operated means for moving one lap toward the other, adjustable means for stopping the relative approach of the laps at a variable but predetermined position, and

means for exerting a variable but predeter.

mined pressure upon the Work by said laps.

9. A lapping machine comprising two horizontally opposed laps and a work cage therebetween which are relatively movable to produce a lapping operation, mechanism for raising or lowering the upper lap, mechanism for stopping the approach of the upper lap at a. predetern'iined but variable position, and manually controllable mechanism for impressing a variable predetermined pressure upon the work by said laps.

10. A lapping machine comprising two horizontally opposed laps and a work cage therebetween which are relatively movable to lap the work, power operated mechanism for moving the upper lap toward or away from the other lap, means for stopping the upper lap in any predetermined position,

work with a pressure which may be varied from a light to a heavy pressure irrespective of the weight of the la and manual y controlled power operate means to rapidly move the laps relatively away from each other on completion of the lapping operation.

14. A lapping machine having two relatively movable opposed lapping members, a work cage positioned therebetween, said parts being relatively movable through an ever-changmg path for lapping the work, power operated mechanism to move a lapping member to any predetermined position relative to the work, including a manually controllable device which makes it possible to press said lapping element against the work with a Variable but predetermined pressure. Signed at Worcester, Massachusetts, this 18th day of October, 1928.

HERBERT S. INDGE. SYDNEY PLAYER.

and means for manually moving the upper Y lap toward the` other and for exerting a variable predetermined pressure upon the-work by said laps.

11. A lapping machine comprising a base, a lap mounted thereon, a .yertica-lly movable,

rotatable lap mounted thekeabove, a work l cage interposed between the laps, power operated mechanism for moving the upper lap toward the lower lap, and manually adjustable mechanism to exert any desired pressure upon the work by the laps.

12. A lapping machine. comprising two horizontally opposed relatively rotatable laps, a work cage therebetween, means for rotating one of the laps, power driven mechanism for raising and lowering the upper lap, mechanism for stopping the approach of the upper lap toward the lower lap at a predetermined position, and manually controllable mechanism for imparting a variable predetermined pressure upon the Work by said laps.

13. A lapping machine comprising two opposed horizontal lapping members, one4 of which is movable vertically towards andl from the other, a rotatable work cage therebetween, means for causing a lapping action upon the work, a manually controlled mechanism for pressing the movable lap against the 

